I'm not talking about unmowed laws that are bad for the economy though. That's a negative externality for which there are many more justifications for governmen

I'm not talking about unmowed laws that are bad for the economy though. That's a negative externality for which there are many more justifications for government intervention (though not for an income tax). It you want to nitpick on my thought experiment, you could also bring up the fact that a lawn is on top of land, and that there are strong moral arguments against an individual having a natural right to absolute private ownership over land, which in turns provides various justifications for government dictating land-use rules and collecting taxes on land/real-estate. But I was not trying to make a comment on negative externalities or the right to private land ownership. I was making the point that the government spending money on something, and this action ending up benefiting you, does not grant the government the moral right to threaten you with imprisonment to force you to pay for that something.